Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Fast parallel algorithms for short-range molecular dynamics

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

J. Appl. Cryst.の発刊に際して

I have developed "tennis elbow" from lugging this book around the past four weeks, but it is worth the pain, the effort, and the aspirin. It is also worth the (relatively speaking) bargain price. Including appendixes, this book contains 894 pages of text. The entire panorama of the neural sciences is surveyed and examined, and it is comprehensive in its scope, from genomes to social behaviors. The editors explicitly state that the book is designed as "an introductory text for students of biology, behavior, and medicine," but it is hard to imagine any audience, interested in any fragment of neuroscience at any level of sophistication, that would not enjoy this book. The editors have done a masterful job of weaving together the biologic, the behavioral, and the clinical sciences into a single tapestry in which everyone from the molecular biologist to the practicing psychiatrist can find and appreciate his or

Principles of Neural Science

This paper studies the microstructure of drawn gold wires to equivalent strain of 10 and to equivalent strain of 8.5 then heat-treated. The texture of gold wire drawn to strain of 10 is mainly composed of and fibers. Tensile strength of the gold wire increases with fiber fraction, while the grain size does not appear to affect the tensile property. With an exception at heat treatment at 600oC, the texture of gold wire drawn the strain of 8.5 is replaced with fiber component by heat treatment process at 400~700oC. Heat treatment at 600oC produces fiber or fiber, depending upon annealing time.

http://engineering.snu.ac.kr/pdf/2005(22)/2005_ksh_high%20tensile%20strength%20of%20drawn%20gold.pdf

High Tensile Strength of Drawn Gold

The thermal annealing effect on the compressive residual stress has been presented in thin diamond-like carbon (DLC) film on Si substrate. Annealing experiments were carried out with Rapid Thermal Procedure system at from 200 to 600 °C, and the variation of residual stress with annealing temperature was investigated by in-situ stress measurement system. The stress reduction occurs as annealing temperature increases, while the change of chemical structure of DLC film is not significantly changed with observation by Raman spectrometer. The elastic modulus and hardness are not deteriorated when annealing temperature is controlled at less than 400 degree of Celsius, where the residual stress is apparently reduced.

The Thermal Annealing Effect on the Residual Stress and Mechanical Property in the Compressive Stressed DLC Film

Deformation characteristics of cold rolled grains and their contribution to the development of recrystallization texture in IF steel were investigated using EBSD. Quantitative evaluation of the intra-granular orientation spread in the deformed grains was attempted. Both of the GAM and SGS could represent the orientation spread but in different manner. The GAM value was higher in {111}//ND orientations than in other orientation groups implying steep orientation gradient within short ranges in {111}//ND oriented grains. This steep orientation gradient was generally originated from the existence of deformation heterogeneities. Particularly, {111} orientation which was the dominant component in the recrystallization texture showed the maximum values of both GAM and SGS, which was caused by the frequent development of shear bands. SGS values of {001}//ND oriented soft grains were unexpectedly large in spite of their small GAM values. It could be confirmed that their uniform deformation behavior led to the gentle but monotonous orientation gradient in long ranges. The lowest values of both GAM and SGS were obtained in the {112} orientation, probably, because of the highest orientation stability in that orientation during plain strain deformation condition. GAM was more closely related to the development of recrystallization texture and the significance of the steep orientation gradient in the recrystallization behavior should be re-addressed.

Orientation Spread in Deformed Grains and Its Relevance to Recrystallization Texture Development in IF Steels

The effects of proton irradiation on a beryllium reflector in terms of microstructure evolution have been studied to emulate the effects of neutron irradiation. Protons were irradiated on a beryllium sample with the acceleration voltage of 120 keV and the fluence of 2.0 × 1018 ions/cm2 at room temperature. The size of the irradiation damaged layer was estimated through a Monte Carlo simulation (SRIM2012 software) and transmission electron microscopy (TEM) observation. While the irradiated sample was observed by using TEM, the size of the damaged layer was roughly 1 µm, and the value was coincident with the simulation result. The most severely damaged area was occurred at 600 nm in depth; tens-of-nanometer-sized voids were distributed. Multiple voids were observed in the entire damaged area, and were preferentially distributed along the grain boundaries, and the interfaces between the matrix and the BeO particles. Equi-axed voids, 10 nm in diameter, were observed in the grain boundary, and planar voids were observed at the interfaces. The voids were also distributed in the grains; the evolutions of the voids were observed to have been affected by the grain orientation rather than the irradiation direction. The selective area diffraction pattern (SADP) from TEM showed that the arrays of multiple voids were considerably longer along the basal plane. The beryllium atoms could be easily dislocated by proton irradiation while the basal plane was aligned along a direction perpendicular to the irradiation.

http://engineering.snu.ac.kr/pdf/2013(23)/2013_KSH_Microstructure%20evolution%20of%20Beryllium%20during%20proton%20irradiation.pdf

Kyu Hwan Oh

Papers

High Tensile Strength of Drawn Gold

The Thermal Annealing Effect on the Residual Stress and Mechanical Property in the Compressive Stressed DLC Film

Orientation Spread in Deformed Grains and Its Relevance to Recrystallization Texture Development in IF Steels

Microstructure evolution of beryllium during proton irradiation

$\bm\beta$-Ga$_{2}$O$_{3}$ Nanowires and Nanobelts Synthesized byUsing GaAs Powder Evaporation